Cylindrical secondary battery

Abstract

A cylindrical secondary battery including: a cylindrical can having an open end in a longitudinal direction thereof; a cap plate coupled to the can and having an opening therein; an electrode assembly accommodated in the can and including a first electrode plate and a second electrode plate; and a first terminal. The first terminal includes: a base block electrically connected to the first electrode plate; a head facing the base block and exposed to the outside through the opening; and a fusible link connecting the base block and the head to each other and having a diameter less than that of the head.

What is claimed is: 
     
         1 . A cylindrical secondary battery comprising:
 a cylindrical can having an open end in a longitudinal direction thereof;   a cap plate coupled to the can and having an opening therein;   an electrode assembly accommodated in the can and comprising a first electrode plate and a second electrode plate; and   a first terminal comprising:
 a base block electrically connected to the first electrode plate; 
 a head facing the base block and exposed to the outside through the opening; and 
 a fusible link connecting the base block and the head to each other and having a diameter less than that of the head. 
   
     
     
         2 . The cylindrical secondary battery as claimed in  claim 1 , wherein the fusible link has an hourglass shape. 
     
     
         3 . The cylindrical secondary battery as claimed in  claim 1 , wherein the fusible link is formed by soldering. 
     
     
         4 . The cylindrical secondary battery as claimed in  claim 1 , wherein the first terminal further comprises an insulation member between the base block and the head. 
     
     
         5 . The cylindrical secondary battery as claimed in  claim 4 , wherein the insulation member is made of a glass to metal sealing material. 
     
     
         6 . The cylindrical secondary battery as claimed in  claim 4 , wherein the insulation member has a protrusion that protrudes further outwardly than a surface of the head. 
     
     
         7 . The cylindrical secondary battery as claimed in  claim 1 , further comprising:
 a first electrode collector plate electrically connected to the first electrode plate and the first terminal; and   a second electrode collector plate electrically connected to the second electrode plate and the can.   
     
     
         8 . The cylindrical secondary battery as claimed in  claim 7 , wherein the can has two open ends in the longitudinal direction,
 wherein the cap plate is coupled to one of the open ends of the can, and   wherein a circular bottom plate is coupled to the other one of the open ends of the can.   
     
     
         9 . The cylindrical secondary battery as claimed in  claim 8 , wherein the first electrode collector plate faces the cap plate, and
 wherein the second electrode collector plate faces the bottom plate.   
     
     
         10 . The cylindrical secondary battery as claimed in  claim 1 , wherein the cap plate comprises:
 a flat first plate part;   an inclined part inclined upwardly from the first plate part;   a second plate part connected to the inclined part and parallel to the first plate part; and   an extension part extending from the second plate part toward the base block.   
     
     
         11 . The cylindrical secondary battery as claimed in  claim 10 , wherein a surface of the second plate part protrudes further outwardly than a surface of the head.